The behavior is like this:

I have Lubuntu automatically logging on at boot and running a VNC server via autostart. I can remote from my Windows 7 machine to the Lubuntu box just fine for a time (using TightVNC viewer on Windows). However, after a while, when I try to connect remotely I get a black screen and a dot shaped cursor on my VNC viewer. It seems to occur rather quickly if the machine is doing something hard drive intensive (such as a backup: I have duplicati making an encrypted backup of about 3gb of data and dropping it into dropbox).

This behavior occurred with two different vnc servers on the lubuntu box: x11vnc and vino. The other software that the server was running (file sharing, dropbox, plex) continued to function fine and I could still SSH into the server without issue. It appears to strictly be a VNC issue.

Killing the VNC server on CLI remotely using Putty and restarting the VNC server did not correct the problem. Only a full reboot corrects the problem temporarily.

The problem appears to not affect tightvncserver. I prefer not to use tightvncserver because it won't let me remotely control display 0...it makes its own session and logs in. This is not the behavior I want.

I really like the performance of LXDE, but I'm about ready to go back Mint XFCE or try Debian XFCE. My hardware is limited (Intel Atom D525 dual core, 1.86ghz, 2gb of ram) so lightweight is important, but I need something that isn't going to up and quit on me whenever it feels like it.

I got tired of fighting Lubuntu (and Debian LXDE and Debian XFCE and Ubuntu minimal with XFCE installed and...well, you get the idea) and just went back to Mint 17, except I purged vino and started running x11vnc instead, which seems to be a better piece of software.